Apogee Instruments SE-100 Manuale d'uso - Pagina 16

Sfoglia online o scarica il pdf Manuale d'uso per Sensori di sicurezza Apogee Instruments SE-100. Apogee Instruments SE-100 18. Photometric sensor

TROUBLESHOOTING AND CUSTOMER SUPPORT

Independent Verification of Functionality

Apogee SE-100 series photometric sensors are self-powered devices and output a voltage signal proportional to

illuminance. A quick and easy check of sensor functionality can be determined using a voltmeter with millivolt

resolution. Connect the positive lead wire from the voltmeter to the white wire from the sensor and the negative

(or common) lead wire from the voltmeter to the black wire from the sensor. Direct the sensor head toward a light

source and verify the sensor provides a signal. Increase and decrease the distance from the sensor head to the

light source to verify that the signal changes proportionally (decreasing signal with increasing distance and

increasing signal with decreasing distance). Blocking all radiation from the sensor should force the sensor signal to

zero.

Compatible Measurement Devices (Dataloggers/Controllers/Meters)

SE-100 series photometric sensors are calibrated with a standard calibration factor of 1000 lux per mV, yielding a

sensitivity of 0.001 mV per lux. Thus, a compatible measurement device (e.g., datalogger or controller) should have

resolution of at least 0.001 mV in order to provide illuminance resolution of 1 lux.

An example datalogger program for Campbell Scientific dataloggers can be found on the Apogee webpage at

https://www.apogeeinstruments.com/content/Photometric-Unamplified.CR1.

Cable Length

When the sensor is connected to a measurement device with high input impedance, sensor output signals are not

changed by shortening the cable or splicing on additional cable in the field. Tests have shown that if the input

impedance of the measurements device is greater than 1 mega-ohm there is negligible effect on the calibration,

even after adding up to 100 m of cable. All Apogee sensors use shielded, twisted pair cable to minimize

electromagnetic interference. For best measurements, the shield wire must be connected to an earth ground. This

is particularly important when using the sensor with long lead lengths in electromagnetically noisy environments.

Modifying Cable Length

See Apogee webpage for details on how to extend sensor cable length:

(http://www.apogeeinstruments.com/how-to-make-a-weatherproof-cable-splice/).